A communication system is provided for transferring data through a digital
switching network. The communication system includes a client modem, a
linecard in communication with the client modem over a local loop, and a
linecard modem interfacing with the linecard and the digital switching
network. The client modem modulates client data to generate modulated
client data for transmission to the linecard over the local loop, and the
linecard modem receives the modulated client data from the linecard and
demodulates the modulated client data to generate the client data for
transmission through the digital switching network. Further, the linecard
modem modulates network data from the digital switching network to
generate modulated network data for transmission to the client modem over
the local loop, and the client modem receives and demodulates the
modulated network data to generate the network data.